Final answer:
The command to set the screen back to normal after using standout mode is 'tput rmso', which turns off this mode.
Step-by-step explanation:
The screen manipulation command that sets the screen back to normal is tput rmso. Among the options provided, tput smso is used to enter standout mode, which often changes the screen's appearance to highlight or emphasize text, whereas tput cup moves the cursor to a specific position on the screen. To return the display to its usual state after standout mode has been enabled by tput smso, the command tput rmso should be used, as it turns off standout mode.